Polyfluoroalkyl nitrogen compounds, processes for their preparation and their use

ABSTRACT

The invention relates to polyfluoroaklyl nitrogen compounds of general formula: RF-(CH2)2-X in which X denotes an isothiocyanate -N=C=S, carbodiimide -N=C=N(CH2)2-R&#39;F or thiourea -NH-CS-A group, A denoting an optionally substituted amino group, and each of the symbols RF and R&#39;F denotes a perfluoroalkyl radical. these compounds, prepared from the corresponding axides RF(CH2)2N3 or amines RF(CH2)2NH2, can be used as surface-active agents or precursors of such agents.

FIELD OF THE INVENTION

The present invention relates to the field of polyfluoro compounds andits subject is more particularly polyfluoroalkyl nitrogen compoundswhich can be applied especially as surface-active agents or asprecursors of such agents.

BACKGROUND OF THE INVENTION

Many fluorine-containing surfactants are already known and, inparticular, quaternary ammonium salts in which a perfluorinated radicalis linked to the quaternary ammonium group (for example trialkylammoniumor pyridinium) by a bridge whose nature has a great influence on theapplication properties. This bridge can be very simple, for example CH₂or C₂ H₄ (U.S. Pat. No. 2,727,923 and French patent No. 1,588,482) ormore complex, for example -C₂ H₄ SO₂ NH(CH₂)₃ (French patent No.2,084,888), -C₂ H₄ S(CH₂)₃ -OCH₂ CH(OH)CH₂ (European patent No.256,980), or the like.

DETAILED DESCRIPTION OF THE INVENTION

The subject of the present invention is now a new group of polyfluorocompounds which can be represented by the general formula:

    R.sub.F --(CH.sub.2).sub.2 --X

in which X denotes the isothiocyanate group --N═C═S, a carbodiimidegroup --N═C═N(CH₂)₂ --R'_(F) or a thiourea group --NH--CS--A, A denotingan optionally substituted amino group, and the symbols R_(F) and R'_(F)may be identical or different and each denotes a linear or branchedperfluoroalkyl radical containing from 2 to 16 carbon atoms, preferably4 to 12.

When the symbol X denotes a thiourea group --NH--CS--A, the group A isadvantageously chosen from groups (A1) to (A6) of following formulae:##STR1## where:

M is equal to 1 or 2,

each of Q and Q', which are identical or different, denotes an alkylenebridge of 2 to 8 carbon atoms,

R denotes an unsubstituted linear alkyl radical containing from 1 to 4carbon atoms,

R¹ denotes a linear or branched alkyl radical containing from 1 to 18carbon atoms and optionally substituted, an optionally substituted arylor aralkyl radical, an allyl, methallyl or propargyl radical, a --(CH₂)₂R'_(F) group or a --QNR₂ group,

R² denotes a hydrogen atom, an alkyl radical as defined for R¹ or,provided that R¹ is an alkyl or allyl radical, an allyl radical,

R³ denotes an alkyl or aralkyl radical as defined for R¹, an allyl,methallyl or propargyl radical or a --CH₂ --S--(CH₂)₂ --R'_(F) group andZ.sup.(-) denotes a monovalent anion or its equivalent.

As substituents which may be present on the alkyl, aryl or aralkylradicals there may be mentioned halogen atoms, hydroxyl, mercapto andnitrile groups and ester, acid, sulphonate, sulphate or carboxylatefunctional groups.

The compounds according to the invention in which X is the --N═C═Sgroup, that is polyfluoroalkyl isothiocyanates of formula:

    R.sub.F --(CH.sub.2).sub.2 --N═C═S                 (I)

can be prepared, in comparable yields, from the correspondingpolyfluoroalkyl azides R_(F) (CH₂)₂ N₃ or polyfluoroalkylamines R_(F)--(CH₂)₂ --NH₂.

The process for preparing isothiocyanates (I) from polyfluoroalkylazides is carried out in a single reactor and comprises two stages:

1) The first consists in forming an iminophosphorane intermediate whichis not isolated, by reacting the azide R_(F) (CH₂)₂ N₃ under inertatmosphere with a triarylphosphine whose aryl radicals may besubstituted by halogen atoms or lower alkyl or alkoxy groups, or elsewith a trialkyl phosphite whose alky radicals may contain from 1 to 4carbon atoms. This reaction is advantageously carried out at atemperature of between 10° and 40° C. and, optionally, in the presenceof an anhydrous aprotic organic solvent such as an ether, a halogenatedor aromatic hydrocarbon or acetonitrile.

2) The second stage consists in reacting the iminotriarylphosphorane oriminotrialkoxyphosphorane intermediate, without preliminary isolation,with carbon sulphide. The addition of the latter is advantageouslyperformed at a temperature of between 0° and 40° C. The reaction timevaries from approximately 2 to 24 hours depending on the phosphorousintermediate used.

The preparation of isothiocyaates (I) from polyfluoroalkylamines is alsocarried out in a single reactor and comprises two stages:

1) The first consists in forming a polyfluoroalkyl dithiocarbamate byreacting the polyfluoroalkylamine R_(F) (CH₂)₂ NH₂, in the presence ofone molar equivalent of an inorganic or organic base, with carbonsulphide, the latter being preferably used in slight excess (0.2 to0.5%). This reaction is advantageously carried out between -10° and +30°C. for a period of approximately 2 to 5 hours, and is then optionallytaken to completion by heating to 90°-100° C. Water is a suitablesolvent, but it is also possible to use methanol or an aqueous solutioncontaining 50-60% of tert-butanol. The base preferably used is sodium orpotassium hydroxide, but another base, for example aqueous ammonia ortriethylamine, may be used; with the latter, dioxane or benzene can beused as a solvent.

2) The second stage consists in subjecting the polyfluoroalkyldithiocarbamate to a carboalkoxylation or an oxidation. Thecarboalkoxylation is carried out by slow addition of one molarequivalent of a lower alkyl (C₁ -C₄) chloroformate at a temperature ofbetween -10° and 40° C. A polyfluoroalkyl carboalkoxydithiocarbamate isformed, which decomposes to a polyfluoroalkyl isothiocyanate accordingto the invention.

The oxidation of the dithiocarbamate intermediate can be carried out byreaction with an alkali metal hypochlorite between 0° and 8° C. in thepresence of a chlorinated solvent (for example chloroform, methylenechloride or carbon tetrachloride) for 0.5 to 3 hours. This method givesa yield of polyfluoroalkyl isothiocyanate of the same order as thecarboalkoxylation method.

The isothiocyanates (I) are valuable intermediates for the synthesis ofprecursors of surface-active agents, especially for that ofpolyfluorocarbodiimides and thioureas.

Thus, for example, the compounds according to the invention, in which Xis an --N═C═N(CH₂)₂ --R'_(F) group, that isN,N'-bis(polyfluoroalkyl)carbodiimides of formula:

    R.sub.F (CH.sub.2).sub.2 --N═C--N(CH.sub.2).sub.2 R'.sub.F (II)

can be prepared by reacting an isothiocyanate (I) with animinotriarylphosphorane obtained as above from a polyfluoroalkyl azide.The process is carried out in a single reactor where, in a first stage,the polyfluoroalkyl azide is converted into an iminotriarylphosphoraneintermediate, which is not isolated but is reacted directly with theisothiocyanate (I) at a temperature of between 60° and 90° C. for aperiod of approximately 6 to 24 hours. This process enables symmetricalas well as unsymmetrical carbodiimides (II) to be obtained.

The symmetrical carbodiimides:

    R.sub.F (CH.sub.2).sub.2 --N═C═N--(CH.sub.2).sub.2 R.sub.F (IIa)

can also be obtained by another method from an azide R_(F) (CH₂)₂ N₃ andcarbon dioxide gas. By operating as above, the azide is first convertedinto an iminotriarylphosphorane intermediate and then, withoutpreliminary isolation and in the same reactor, this intermediate isreacted with carbon dioxide gas.

The carbodiimides (II) according to the invention are valuableintermediates for the synthesis of precursors of surface-active agentsand of fluoroureas. They can also be used as stabilizers for natural orsynthetic polymers, increasing their resistance to hydrolysis. Inaddition, they can be used for producing neutral lubricating oils or,yet again, as monomers which lead to highly hydrophobic plastics.

The compounds according to the invention in which X is a thiourea group--NH--CS--A, that is the compounds of formula: ##STR2## are preparedfrom the isothiocyanates of formula (I).

Thus, the monosubstituted thioureas of formula: ##STR3## can be obtainedby reaction of aqueous ammonia with an isothiocyanate (I). This reactionis advantageously carried out at a temperature of between 20° and 80° C.by using an aqueous solution containing 28-30% of NH₄ OH in a proportionof three moles of aqueous ammonia per mole of isothiocyanate. In theseconditions, a monosubstituted thiourea (IIIa) is obtained, sufficientlypure to be usable directly.

The di- or trisubstituted thioureas of formula: ##STR4## are obtained byreacting the corresponding primary or secondary amine HNR¹ R² with anisothiocyanate (I). The reaction is preferably carried out at atemperature of between 0° and 40° C., optionally in an inert organicsolvent such as, for example, an ether, a halogenated hydrocarbon oracetonitrile.

Among the thioureas (IIIb), those in which R¹ denotes adialkylaminoalkyl group and R² denotes a hydrogen atom, that is thecompounds of formula: ##STR5## have a tertiary amine functional groupwhich makes them reactive towards quaternizing agents. Thus, thecompounds of formula (III) in which A denotes a nitrogen group (A3),that is the ammonium salts of formula: ##STR6## can be prepared byreaction of a thiourea (IIIc) with a quaternizing agent, for example anoptionally functionalized alkyl halide. The reaction is preferablycarried out by dissolving substantially equimolar quantities of thiourea(IIIc) and of the chosen quaternizing agent in an inert anhydrousorganic solvent (for example an ether, a halogenated hydrocarbon oracetonitrile) at a temperature of between 20° and 80° C. The reactiontime and the physical appearance of the salts (IIId) which are formedvary depending on the nature of the chosen quaternizing agent. However,most of the salts (IIId) are colorless pastes or oils and arehygroscopic; to a different extent, they are all soluble in water andform neutral solutions.

Nonlimiting examples of quaternizing agents which may be mentioned moreparticularly are alkyl iodides (1 to 18 carbon atoms), allyl bromide,hydroxyethyl bromide, benzyl bromide, alkyl bromides (4 to 18 carbonatoms) and polyfluoroalkylthiomethyl bromides R'_(F) (CH₂)₂ --S--CH₂ Br,described in French patent no. 2,592,648.

Provided that a double molar proportion of thiourea (IIIc) is used, itis also possible to use as quaternizing agents alkyl dihalides such as,for example, 1,2-dibromoethane, 1,3-dibromopropane, 1,2-diiodoethane,1,3-diiodopropane and 1,4-diiodobutane. Compounds of formula (III) arethen obtained, in which A denotes the group (A4), that is the doublesalts of formula: ##STR7##

The anion Z.sup.(-) of the ammonium salts (IIId) and (IIIe) can, ifdesired, be easily exchanged for another anion using methods which areknown per se. More specific examples of anions which may be mentionedare halide, nitrate, p-toluenesulphonate, sulphate, alkylsulphate andpicrate ions.

The compounds of formula (III) in which A denotes a group (A5), namelythe N-oxides of formula: ##STR8## can be prepared by reaction ofhydrogen peroxide with a thiourea (IIIc) in an inert solvent (forexample an ether or acetonitrile) at a temperature of between 60° and80° C. These oxides are obtained in the form of pastes and are allwater-soluble.

The compounds of formula (III) for which A denotes the group (A6), thatis the betaines of formula: ##STR9## can be prepared by the action ofsodium chloroacetate or of beta-propiolactone on a thiourea (IIIc). Thereaction is advantageously carried out at a temperature of between 30°and 90° C. in an inert organic solvent (for example an alcohol ortrichlorotrifluoroethane). The betaines (IIIg) are obtained in the formof pastes; they are all water-soluble.

The ammonium salts (IIId) and (IIIe), the N-oxides (IIIf) and thebetaines (IIIg) are valuable surface-active agents which can be employedas additives in a very wide variety of fields as wetting agents,emulsifiers, dispersants or foaming agents.

EXAMPLES

The following examples illustrate the invention without limiting it.

EXAMPLE 1

0.02 moles of 2-perfluorobutylethyl azide C₄ F₉ --C₂ H₄ --N₃ areintroduced into a reactor placed under nitrogen atmosphere and equippedwith a magnetic stirrer and a dropping funnel containing 0.02 moles oftriphenylphosphine in solution in 26 ml of anhydrous tetrahydrofuran,and the triphenyl phosphine solution is then added dropwise at roomtemperature.

After being stirred for one hour at room temperature, the solution iscooled to 0° C. by means of an ice bath, and 15 g of carbon sulphide arethen added dropwise. When the addition is finished the ice bath isremoved and stirring is continued for two hours.

The tetrahydrofuran and the excess carbon sulphide are then evaporatedoff under vacuum and the residue is then taken up with petroleum etherand filtered. After evaporation of the solvent under vacuum2-perfluorobutylethyl isothiocyanate C₄ F₉ --C₂ H₄ --NCS, which boils at48° C. at 4 kPa, is obtained in a 69% yield.

This isothiocyanate was identified by the following data:

    ______________________________________                                        Elemental analysis:                                                                   C %     H %    F %       N %  S %                                     ______________________________________                                        measured  27.61     1.33   56.00   4.54 10.49                                 calculated                                                                              27.54     1.31   56.06   4.59 10.50                                 ______________________________________                                    

Infrared spectrum

ν.sub.(C-F) =1050-1350 cm⁻¹

ν.sub.(NCS) =2075 cm⁻¹ shoulder at 2190 cm⁻¹

¹ H NMR spectrum recorded in solution in CDCl₃, the chemical shiftsbeing given in ppm relative to TMS:

split triplet at 2.51 ppm (2H integration, ³ J_(H-F) =13.5 Hz and ³J_(H-H) =5.6 Hz)

triplet at 3.86 ppm (2H integration, ³ J_(H-H) =5.6 Hz)

¹⁹ F NMR spectrum recorded in solution in CDCl₃, the chemical shiftsbeing given in ppm relative to CFCl₃ : ##STR10##

Mass spectrometry

M⁺ =305 (29%); m/z 156 (22%); m/z 126 (16%); m/z 110 (21%); m/z 93(63.5%); m/z 72 (100%); m/z 69 (20.5%).

EXAMPLE 2

The procedure is as in Example 1, but replacing 2-perfluorobutylethylazide with the same molar quantity of 2-perfluorohexylethyl azide. Thecorresponding isothiocyanate C₆ F₁₃ --C₂ H₄ --NCS is obtained in a 70%yield (B.p.=87°-91° C./2.67 kPa).

This isothiocyanate was identified by the following data:

    ______________________________________                                        Elemental analysis:                                                                   C %     H %    F %       N %  S %                                     ______________________________________                                        measured  26.55     1.11   60.97   3.50 7.86                                  calculated                                                                              26.67     0.99   60.98   3.45 7.90                                  ______________________________________                                    

¹⁹ F NMR spectrum ##STR11##

Mass spectrometry

M⁺ =405 (87%); m/z 386 (2.5%); m/z 136 (2%); m/z 131 (15%); m/z 119(22%); m/z 108 (11.5%); m/z 72 (99%); m/z 59 (100%).

IR and ¹ H NMR spectra: identical with those of the isothiocyanate ofExample 1.

EXAMPLE 3

The procedure is as in Example 1, but replacing 2-perfluorobutylethylazide with the same molar quantity of 2-perfluorooctylethyl azide. Thecorresponding isothiocyanate C₈ F₁₇ --C₂ H₄ --NCS is obtained in a 73%yield (B.p.=113°-15° C./4 kPa).

This isothiocyanate has the following characteristics:

    ______________________________________                                        Elemental analysis:                                                                   C %     H %    F %       N %  S %                                     ______________________________________                                        measured  26.30     0.78   63.85   2.72 6.34                                  calculated                                                                              26.13     0.79   63.96   2.77 6.33                                  ______________________________________                                    

IR and ¹ H NMR spectra: identical with those of the isothiocyanate ofExample 1.

¹⁹ F NMR spectrum ##STR12##

Mass spectrometry

M⁺ =505 (46.5%); m/z 119 (15%); m/z 72 (100%); m/z 69 (34.5%); m/z 59(57%).

EXAMPLE 4

0.02 moles of 2-perfluorohexylethyl azide are introduced into a reactorplaced under a nitrogen atmosphere and equipped with a magnetic stirrerand a dropping funnel containing 0.02 moles of trimethyl phosphite insolution in 26 ml of anhydrous tetrahydrofuran, and the trimethylphosphite solution is then added at room temperature.

After 20 hours' stirring, 15 g of carbon sulphide are added dropwise atroom temperature. Stirring is then continued for 24 hours and thetetrahydrofuran and excess carbon sulphide are then evaporated off underreduced pressure, and the residue is distilled. 2-Perfluorohexylethylisothiocyanate is thus obtained in a 55% yield (B.p.=87°-91° C./2.67kPa).

EXAMPLE 5

0.66 g of caustic soda in 3.6 ml of water and 1.258 g of carbon sulphideare placed in a reactor equipped with a magnetic stirrer, a condenserand a dropping funnel. 0.0165 moles of 2-perfluorobutylethylamine C₄ F₉--C₂ H₄ --NH₂ are added very slowly. The reaction mixture turns orangeand becomes pasty. 2.5 to 3 ml of water are added and stirring iscontinued for two hours at room temperature, and then for 15 minutes at90° C. The mixture is then cooled to 40° C. and 0.0165 moles of methylchloroformate are added slowly. Stirring is continued for one hour atroom temperature, followed by extraction with ether, drying over sodiumsulphate and evaporation. When the residue is distilled,2-perfluorobutylethyl isothiocyanate is obtained in a 65% yield(B.p.=48° C./4kPa).

EXAMPLE 6

The procedure is as in Example 5, but replacing2-perfluorobutylethylamine with the same molar quantity of2-perfluorohexylethylamine. 2-Perfluorohexylethyl isothiocyanate isobtained in a 76% yield (B.p.=90° C./2.67 kPa).

EXAMPLE 7

The procedure is as in Example 5, but replacing2-perfluorobutylethylamine with the same molar quantity of2-perfluorooctylethylamine. 2-Perfluorooctylethyl isothiocyanate isobtained in a 67% yield (B.p.=113°-15° C./4 kPa).

EXAMPLE 8

0.66 g of caustic soda in 3.6 ml of water and 1.258 g of carbon sulphideare placed in a reactor equipped with a magnetic stirrer, a condenserand a dropping funnel. 0.0165 moles of 2-perfluorobutylethylamine areadded very slowly via the dropping funnel. The reaction mixture turnsorange and becomes pasty. 2.5 to 3 ml of water are then added andstirring is continued for two hours at room temperature and then for 15minutes at 90° C. The mixture is then cooled to 0° C. and 16 ml of waterand 10 ml of methylene chloride are added, following by a solution of 33ml of sodium hypochlorite at a strength of 10-13 French chlorometrydegrees (d=1.05), to which 2.65 g of caustic soda have been added. Themixture changes from yellow to milky white. When the addition isfinished, stirring is continued for one hour and an extraction withether is then carried out, followed by drying over sodium sulphate andevaporation. When the residue is distilled, 2-perfluorobutylethylisothiocyanate is obtained in a 62% yield (B.p.=48° C./4 kPa).

EXAMPLE 9

The procedure is as in Example 8, but replacing2-perfluorobutylethylamine with the same molar quantity of2-perfluorohexylethylamine. The corresponding isothiocyanate is obtainedin a 65% yield (B.p.=90° C./2.67 kPa).

EXAMPLE 10

The procedure is as in Example 8, but replacing2-perfluorobutylethylamine with the same molar quantity of2-perfluorooctylethylamine. The corresponding isothiocyanate is obtainedin a 70% yield (B.p.=113°-15° C./4 kPa; mp=50° C.).

EXAMPLE 11

0.02 moles of 2-perfluorohexylethyl azide are introduced into a reactorplaced under a nitrogen atmosphere and equipped with a magnetic stirrerand a dropping funnel containing 0.02 moles of triphenylphosphine insolution in 26 ml of anhydrous tetrahydrofuran and the triphenylphosphine solution is then added dropwise at room temperature.

After one hour's stirring, carbon dioxide gas obtained by sublimation ofcarbon dioxide snow and predried over anhydrous CaCl₂ is bubbled intothe reaction mixture.

After one hour's reaction, the solvent is evaporated off and the residueis taken up with petroleum ether. This is filtered to remove the solidtriphenylphosphine oxide and the petroleum ether is then evaporated offunder vacuum and the residue is distilled under nitrogen atmosphere.

N,N'-bis(2-perfluorohexylethyl)carbodiimide: C₆ F₁₃ --C₂ H₄ --N═C═N--C₂H₄ --C₆ F₁₃ is thus obtained in a 70% yield (B.p.=101° C./4 kPa).

If white solid particles are present in the product after distillation,the carbodiimide must be filtered to remove this small quantity of ureaformed during the distillation.

EXAMPLE 12

The procedure is as in Example 11, but replacing 2-perfluorohexylethylazide with the same molar quantity of 2-perfluorobutylethyl azide. Thecorresponding carbodiimide C₄ F₉ --C₂ H₄ --N═C═N--C₂ H₄ --C₄ F₉, isobtained in a 68% yield (B.p.=67°-70° C./133 Pa, distillation under N₂).

EXAMPLE 13

The procedure as in Example 11, but replacing 2-perfluorohexylethylazide with the same molar quantity of 2-perfluorooctylethyl azide andpetroleum ether with 1,1,2-trichloro-1,2,2-trifluoroethane. Thecorresponding carbodimide C₈ F₁₇ --C₂ H₄ --N═C═N--C₂ H₄ --C₈ F₁₇ isobtained in a 65% yield (bulb tube distillation, oven temperature: 120°C./10 Pa).

EXAMPLE 14

0.01 mole of 2-perfluorohexylethyl azide is introduced into a reactorplaced under nitrogen atmosphere and equipped with a magnetic stirrerand a dropping funnel containing 0.01 mole of triphenylphosphine insolution in 13 ml of anhydrous tetrahydrofuran. The triphenylphosphinesolution is then added dropwise at room temperature.

After one hour's stirring, a solution of 0.01 mole of2-perfluorohexylethyl isothiocyanate in 13 ml of tetrahydrofuran isadded via the dropping funnel.

If the reaction, which is followed by gas phase chromatography, is notfinished after 12 hours' stirring at ambient temperature, heating to 70°C. is applied for a few hours.

The tetrahydrofuran is then evaporated off under vacuum and the residueis taken up with petroleum ether. The triphenylphosphine sulphide formedis filtered off and then the petroleum ether is stripped off undervacuum and the residue is distilled under nitrogen atmosphere.

N,N'-bis(2-perfluorohexylethyl)carbodiimide is thus obtained in a 78%yield (B.p.=101° C./4 kPa).

EXAMPLE 15

The procedure is as in Example 14, but replacing 2-perfluorohexylethylazide with the same molar quantity of 2-perfluorobutylethyl azide and2-perfluorohexylethyl isothiocyanate with the same molar quantity of2-perfluorobutylethyl isothiocyanate.

N,N'-bis(perfluorobutylethyl)carbodiimide is obtained in a 75% yield(B.p.=67°-70° C./133 Pa, distillation under N₂).

EXAMPLE 16

The procedure as in Example 14, but replacing 2-perfluorohexylethylazide with the same molar quantity of 2-perfluorobutylethyl azide.

N-(2-perfluorobutylethyl)-N'(2-perfluorohexylethyl) carbodiimide C₄ F₉--C₂ H₄ --N═C═N--C₂ H₄ --C₆ F₁₃ is obtained in a 60% yield (B.p.=97°C./4 kPa, distillation under N₂).

The carbodiimides of Examples 11 to 16 were identified by elementalanalysis, infrared, proton and fluorine NMR and mass spectrometry. Thedata corresponding to the elemental analysis and to the massspectrometry are collated in Table 1, which follows.

                                      TABLE 1                                     __________________________________________________________________________     CARBODIIMIDE  C(NC.sub.2 H.sub.4 C.sub.4 F.sub.9).sub.2                                               C(NC.sub.2 H.sub.4 C.sub.6 F.sub.13).sub.2                                              C(NC.sub.2 H.sub.4 C.sub.8 F.sub.17).su                                      b.2                                                                                      ##STR13##                        __________________________________________________________________________    Elemental analysis                                                            C % measured (calculated)                                                                   29.28 (29.21)                                                                           28.01 (27.79)                                                                           27.24 (26.98)                                                                           28.04 (28.39)                     H % measured (calculated)                                                                    1.68 ( 1.50)                                                                            1.07 ( 1.09)                                                                            1.14 ( 0.86)                                                                            1.15 ( 1.26)                     F % measured (calculated)                                                                   64.00 (64.04)                                                                           66.95 (67.30)                                                                           69.17 (69.16)                                                                           66.24 (65.93)                     N % measured (calculated)                                                                    5.11 ( 5.24)                                                                            3.90 ( 3.81)                                                                            2.43 ( 3.00)                                                                            4.55 ( 4.42)                     Mass spectrum                                                                               M.sup.+. = 534 (10%)                                                                    M.sup.+. = 734 (3%)                                                                     M.sup.+. = 934 (8%)                                                                     M.sup.+. = 634 (11.5%)                          m/z 515 (3%)                                                                            m/z 715 (4.5%)                                                                          m/z 915 (7.5%)                                                                          m/z 615 (8.5%)                                  m/z 301 (100%)                                                                          m/z 401 (100%)                                                                          m/z 501 (100%)                                                                          m/z 401 (100%)                                  m/z 119 (7%)                                                                            m/z 119 (4.5%)                                                                          m/z 169 (7%)                                                                            m/z 301 (99%)                                   m/z  69 (12.5%)                                                                         m/z  69 (13%)                                                                           m/z 119 (5%)                                                                            m/z 119 (12%)                                   m/z  55 (99%)                                                                           m/z  55 (82%)                                                                           m/z  69 (18%)                                                                           m/z  81 (11.5%)                                                     m/z  55 (90%)                                                                           m/z  69 (40%)                                                                 m/z  55 (99%)                     __________________________________________________________________________

In the case of all the carbodiimides the IR spectra give:

ν_(C-F) =1000-1300 cm⁻¹

ν_(N)═C═N =2125 cm⁻¹

The ¹ H NMR spectra are identical with those of the isothiocyanatesRFC2H4NCS (signals, integration, coupling constants).

In ¹⁹ F NMR, the spectra of symmetrical carbodiimides (Examples 11 to15) are identical with those of the corresponding isothiocyanates. Inthe case of the unsymmetrical carbodiimide of Example 16, the twoterminal CF₃ groups show the same chemical shift and resonate at -81.5ppm; the two CF₂ α and the two CF₂ ω also have the same chemical shift,at -115.0 and -126.7 ppm respectively; the other CF₂ groups give asystem of four peaks between -125.1 and -122.0 ppm whose relativeintegration corresponds to eight fluorine atoms.

EXAMPLE 17

0.01 mole of 2-perfluorohexylethyl isothiocyanate is introduced at roomtemperature into a reactor equipped with a condenser and fitted with amagnetic stirrer and 6.6 g of a 28-30% solution of NH40H are then addeddropwise. The reaction mixture is then stirred for one hour at roomtemperature and the condenser is then removed and the mixture is heatedat 70-80° C. for 2 hours in order to evaporate off the excess aqueousammonia. The white solid formed is dried andN-(2-perfluorohexylethyl)thiourea C₆ F₁₃ --C₂ H₄ --NH--CS--NH₂ whichmelts at 126° C. and has the following analytical characteristics isthus obtained in an 89% yield:

    ______________________________________                                        Elemental analysis:                                                                   C %     H %    F %       N %  S %                                     ______________________________________                                        measured  25.83     1.52   58.74   6.64 7.50                                  calculated                                                                              25.60     1.66   58.63   6.63 7.58                                  ______________________________________                                    

IR spectrum

ν_(C-F) =1100-1300 cm⁻¹

ν_(NH2) =3400 cm⁻¹

ν_(NH) =3290 cm⁻¹

ν_(C=S) =1580 cm⁻¹

¹ H NMR spectrum recorded in acetone-d₆, the chemical shifts being givenin ppm relative to TMS:

broadened singlet at 7.37 ppm (1H integration)

ill-resolved signal at 6.75 ppm (2H integration)

multiplet at 2.62 ppm (split triplet - 2H

integration, ³ J_(H-F) =13.5 Hz; ³ J_(H-H) =7.5 Hz)

quadruplet at 3.87 ppm (2H integration, ³ J_(H-H) =

6.5 Hz through the nitrogen atom).

¹⁹ F NMR spectrum recorded in acetone-d₆, the chemical shifts beinggiven relative to CFCl₃ : ##STR14##

Mass spectrometry

M⁺ =422 (42%); m/z 389 (4%); m/z 362 (12%); m/z 153 (5.5%) m/z 103(25%); m/z 69 (33.5%); m/z 55 (100%).

By following the same procedure with 2perfluorobutylethylisothiocyanate, N-(2-perfluorobutylethyl) thiourea, which melts at 113°C. and has the following characteristics, is obtained in a 90% yield:

    ______________________________________                                        Elemental analysis:                                                                   C %     H %    F %       N %  S %                                     ______________________________________                                        measured  25.88     2.03   53.25   8.85 10.00                                 calculated                                                                              26.08     2.17   53.10   8.70 9.94                                  ______________________________________                                    

IR and ¹ H spectra identical with those of the preceding compound.##STR15##

Mass spectrometry

M⁺ =322 (49%); m/z 289 (11%); m/z 201 (11.5%); m/z 103 (15.5%) m/z 77(23%); m/z 69 (68%); m/z 60 (62%); m/z 55 (100%).

EXAMPLE 18

The N,N'-disubstituted and N,N',N'-trisubstituted thioureas of formula:##STR16## are prepared from the amines NHR¹ R² by proceeding as follows:

0.01 mole of the amine NHR¹ R² in solution in 15 ml of ethyl ether (orof ethanol in the case where the amine used is diethanolamine) isintroduced into a round bottom reactor fitted with a magnetic stirrerand a dropping funnel containing 0.01 mole of 2-perfluoroalkylethylisothiocyanate R_(F) C₂ H₄ NCS previously dissolved in 15 ml of ethylether, and the isothiocyanate R_(F) C₂ H₄ NCS solution is then addedwith stirring at room temperature. The reaction is practicallyimmediate.

Stirring is nevertheless continued until all the isothiocyanate isconsumed. Depending on the nature of the starting amine, the producteither precipitates in the reaction medium or does not do so. In allcases it suffices to strip off the solvent in the rotary evaporator andto wash the residue thus obtained abundantly with petroleum ether.

The thioureas of formula (IV) are thus obtained in most cases in theform of a white solid, sometimes in the form of a translucent oil. Theirmelting points and the reaction yields are shown in the sixth and fifthcolumns of Table 2, which follows, the number Tx of the first columnbeing used to identify each product.

The results obtained from the elemental analysis and mass spectrometryare collated in Tables 3 and 4.

                                      TABLE 2                                     __________________________________________________________________________    THIOUREAS OF FORMULA (IV)                                                      No.                                                                              R.sub.F                                                                           R.sup.1  R.sup.2  Yld (%)                                                                            Mp (°C.)                                __________________________________________________________________________    T1  C.sub.4 F.sub.9                                                                   CH.sub.2 --CH═CH.sub.2                                                             H        77   (oil)                                          T2  C.sub.6 F.sub.13                                                                  CH.sub.2 --CH═CH.sub.2                                                             H        88   30                                             T3  C.sub.8 F.sub.17                                                                  CH.sub.2 --CH═CH.sub.2                                                             H        83   80-82                                          T4  C.sub.4 F.sub.9                                                                   CH.sub.2 --CH═CH.sub.2                                                             CH.sub.2 --CH═CH.sub.2                                                             95   (oil)                                          T5  C.sub.6 F.sub.13                                                                  CH.sub.2 --CH═CH.sub.2                                                             CH.sub.2 --CH═CH.sub.2                                                             70   (oil)                                          T6  C.sub.8 F.sub.17                                                                  CH.sub.2 --CH═CH.sub.2                                                             CH.sub.2 --CH═CH.sub.2                                                             78   30                                             T7  C.sub.4 F.sub.9                                                                   C.sub.2 H.sub.4 N(CH.sub.3).sub.2                                                      H        77   62                                             T8  C.sub.6 F.sub.13                                                                  C.sub.2 H.sub.4 N(CH.sub.3).sub.2                                                      H        92   63                                             T9  C.sub.8 F.sub.17                                                                  C.sub.2 H.sub.4 N(CH.sub.3).sub.2                                                      H        87   80                                             T10 C.sub.4 F.sub.9                                                                   C.sub.3 H.sub.6 N(CH.sub.3).sub.2                                                      H        83   36                                             T11 C.sub.6 F.sub.13                                                                  C.sub.3 H.sub.6 N(CH.sub.3).sub.2                                                      H        85   52-53                                          T12 C.sub.8 F.sub.17                                                                  C.sub.3 H.sub.6 N(CH.sub.3).sub.2                                                      H        87   71-73                                          T13 C.sub.4 F.sub.9                                                                   C.sub.2 H.sub.4 OH                                                                     C.sub.2 H.sub.4 OH                                                                     93   (oil)                                          T14 C.sub.6 F.sub.13                                                                  C.sub.2 H.sub.4 OH                                                                     C.sub.2 H.sub.4 OH                                                                     96   (oil)                                          T15 C.sub.6 F.sub.13                                                                  phenyl   H        82   93                                             T16 C.sub.8 F.sub.17                                                                  phenyl   H        80   117                                            T17 C.sub.4 F.sub.9                                                                   C.sub.4 H.sub.9                                                                        H        89   56                                             T18 C.sub.6 F.sub.13                                                                  C.sub.4 H.sub.9                                                                        H        71   67                                             T19 C.sub.6 F.sub.13                                                                  C.sub.8 H.sub.17                                                                       H        84   73                                             T20 C.sub.8 F.sub.17                                                                  C.sub.8 H.sub.17                                                                       H        91   85                                             T21 C.sub.4 F.sub.9                                                                   C.sub.2 H.sub.4 C.sub.4 F.sub.9                                                        H        70   67                                             T22 C.sub.6 F.sub.13                                                                  C.sub.2 H.sub.4 C.sub.4 F.sub.9                                                        H        82   73                                             T23 C.sub.6 F.sub.13                                                                  C.sub.2 H.sub.4 C.sub.6 F.sub.13                                                       H        87   88                                             T24 C.sub.8 F.sub.17                                                                  C.sub.2 H.sub.4 C.sub.4 F.sub.9                                                        H        80   86-87                                          __________________________________________________________________________

                  TABLE 3                                                         ______________________________________                                        Percentage analysis of thioureas T1 to T24                                    THIOUREA No.                                                                             C %       H %    F %    N %  S %                                   ______________________________________                                        T1         32.42     3.09   47.06  7.78 8.66                                  T2         31.29     2.45   53.01  6.12 7.12                                  T3         26.95     2.12   57.74  4.70 5.49                                  T4         39.02     3.75   42.88  6.93 7.43                                  T5         36.05     3.12   49.02  5.63 6.17                                  T6         33.69     2.44   53.66  4.29 5.90                                  T7         33.72     4.27   43.24  10.55                                                                              8.22                                  T8         31.67     3.12   50.00  8.55 6.64                                  T9         30.10     2.85   54.55  7.06 5.45                                  T10        35.21     4.43   41.85  10.61                                                                              7.89                                  T11        33.43     3.27   48.75  8.23 6.32                                  T12        31.60     3.21   53.25  6.68 5.26                                  T13        32.30     3.82   41.75  6.73 7.77                                  T14        30.73     2.90   48.30  5.52 6.26                                  T15        36.27     2.13   49.73  5.83 6.05                                  T16        34.27     1.89   53.87  4.57 5.39                                  T17        34.78     4.09   45.25  7.38 8.48                                  T18        32.89     3.25   51.05  5.78 7.02                                  T19        38.25     4.30   46.38  5.37 5.70                                  T20        35.75     3.58   51.15  4.40 5.10                                  T21        27.73     1.89   60.10  4.79 5.50                                  T22        26.81     1.65   62.87  4.33 4.34                                  T23        26.81     1.45   64.55  3.68 3.91                                  T24        26.43     1.38   64.40  3.70 4.08                                  ______________________________________                                    

                  TABLE 4                                                         ______________________________________                                        THIOU-                                                                        REA No. MASS SPECTRUM                                                         ______________________________________                                        T1      M.sup.+  · 362 (15%), m/z 347 (30%), m/z 72 (100%),                  m/z 69 (57.5%)                                                        T2      M.sup.+  · 462 (18.5%), m/z 447 (35%), m/z 405 (16%),                m/z 72 (100%), m/z 69 (50.5%), m/z 57 (88.5%)                         T3      M.sup.+  · 562 (21%), m/z 72 (100%), m/z 69 (50%),                   m/z 57 (91.5%).                                                       T4      M.sup.+  · 402 (23%), m/z 56 (100%), m/z 41 (87%),                   m/z 69 (43%),                                                         T5      M.sup.+  · 502 (12%), m/z 56 (100%), m/z 41 (90%),           T6      M.sup.+  · 602 (28%), m/z 56 (100%), m/z 41 (84%),                   m/z 77 (23%), m/z 69 (33%)                                            T7      M.sup.+  · 393 (6%), m/z 72 (96.5%), m/z 71 (100%),                  m/z 69 (49%)                                                          T8      M.sup.+  · 493 (6%), m/z 71 (77.5%), m/z 58 (100%)           T9      M.sup.+  · 593 (6.5%), m/z 71 (75%), m/z 72 (97%),                   m/z 58 (100%)                                                         T10     M.sup.+  · 407 (10%), m/z 72 (10%), m/z 86 (14%),                    m/z 58 (100%)                                                         T11     M.sup.+  · 507 (9%), m/z 72 (13%), m/z 58 (100%)             T12     M.sup.+  · 607 (10%), m/z 72 (15.5%), m/z 58 (100%)          T13     (M + 1).sup.+  411 (3%), M.sup.+  · 410 (2%), m/z 74                 (81%)                                                                         m/z 43 (100%), m/z 69 (47.5%)                                         T14     (M + 1).sup.+  511 (3%), M.sup.+  · 510 (1.5%), m/z 74               (81%)                                                                         m/z 57 (60%), m/z 43 (100%), m/z 69 (49%)                             T15     M .sup.+  · 498 (45%), m/z 465 (18.5%), m/z 93 (100%),               m/z 77 (76.5%), m/z 69 (46%)                                          T16     M.sup.+  · 598 (40%), m/z 565 (21.5%), m/z 93 (100%),                m/z 77 (79.5%), m/z 69 (47.5)                                         T17     M.sup.+  · 398 (20%), m/z 72 (75%), m/z 44 (100%)            T18     M.sup.+  · 478 (21%), m/z 72 (71%), m/z 44 (100%)            T19     M.sup.+  · 526 (24%), m/z 72 (73%), m/z 44 (100%)            T20     M.sup.+  · 626 (21.5%), m/z 72 (47%), m/z 69 (27.5%),                m/z 44 (100%)                                                         T21     M.sup.+  · 568 (27.5%), m/z 119 (10%), m/z 69 (20%),                 m/z 44 (100%)                                                         T22     M.sup.+  · 668 (20%), m/z 119 (11.5%), m/z 69 (20%),                 m/z 44 (100%)                                                         T23     M.sup.+  · 768 (20%), m/z 119 (8%), m/z 69 (20%),                    m/z 44 (100%)                                                         T24     M.sup.+  · 768 (26%), m/z 119 (11%), m/z 69 (24.5%),                 m/z 44 (100%)                                                         ______________________________________                                    

The IR spectra of all the thioureas were recorded as a KBr disc, withthe exception of the five oily products T1, T4, T5, T13, T14), in thecase of which the spectra were produced in solution in CHCl₃. For agiven single series, the spectrum is independent of the radical R_(F) :

    ______________________________________                                        Thioureas T1 to T3:                                                                            .sup.ν C--F =                                                                        1100- 1350 cm.sup.-1                                                .sup.ν C═S =                                                                     1580 cm.sup.-1                                                      .sup.ν N--H =                                                                        3300 cm.sup.-1                                                      .sup.ν C--H =                                                                        700- 900 cm.sup.-1                                                  .sup.ν C═C =                                                                     1653 cm.sup.-1                                     Thioureas T4 to T6:                                                                            .sup.ν C--F =                                                                        1100- 1350 cm.sup.-1                                                .sup.ν C═S =                                                                     1530 cm.sup.-1                                                      .sup.ν N--H =                                                                        3320 cm.sup.-1                                                      .sup.ν C═C =                                                                     1650 cm.sup.-1                                     Thioureas T7 to T12:                                                                           .sup.ν C--F =                                                                        1100- 1350 cm.sup.-1                                                .sup.ν C═S =                                                                     1580 cm.sup.-1                                                      .sup.ν N--H =                                                                        3300, 3380 cm.sup.-1                                                .sup.ν C--H =                                                                        680- 900 cm.sup.-1                                 Thioureas T13 and T14:                                                                         .sup.ν C--F =                                                                        1100- 1300 cm.sup.-1                                                .sup.ν C═S =                                                                     1585 cm.sup.-1                                                      .sup.ν N--H =                                                                        3200 cm.sup.-1                                                      .sup.ν O--H =                                                                        3320 cm.sup.-1                                     Thioureas T15 and T16:                                                                         .sup.ν C--F =                                                                        1050- 1350 cm.sup.-1                                                .sup.ν N--H =                                                                        3209, 3377 cm.sup.-1                                                .sup.ν C--S =                                                                        1555 cm.sup.-1                                                      .sup.ν C--H =                                                                        650, 694, 737 cm.sup.-1                            Thioureas T17 to T20:                                                                          .sup.ν C--F =                                                                        1000- 1350 cm.sup.-1                                                .sup.ν N--H =                                                                        3280 cm.sup.-1                                                      .sup.ν C═S =                                                                     1570 cm.sup.-1                                                      .sup.ν C--H =                                                                        850, 890 cm.sup.-1                                 Thioureas T21 to T24:                                                                          .sup.ν C--F =                                                                        1000- 1350 cm.sup.-1                                                .sup.ν N--H =                                                                        3380 cm.sup.-1                                                      .sup.ν C═S =                                                                     1637 cm.sup.-1                                     ______________________________________                                    

The ¹ H NMR spectra of thioureas T1 to T24 were recorded in acetone-d₆.All of them show a split triplet of 2H integration at 2.60 ppm (³J_(H-F) =19.5 Hz; ³ J_(H-H3) =6.5 Hz) and a quadruplet, also of 2Hintegration, at 3.90 ppm (³ J_(H-H) =6.5 Hz - coupling through thenitrogen atom); these two signals correspond to the CH₂ bonded to theR_(F) radical and to the CH₂ bonded to the NH group respectively. In thecase of each series, the nature of the radical R_(F) does not effect thespectra, the other signals observed being the following:

    ______________________________________                                        Thioureas T1 to T3:                                                                            broadened signal at 7.1 ppm                                                   (2H integ.)                                                                   triplet at 4.17 ppm                                                           (.sup.3 J = 6.5 Hz - 2H integ.)                                               multiplet between 4.91 and                                                    5.35 ppm (2H)                                                                 multiplet between 5.62 and                                                    6.17 ppm (1H)                                                Thioureas T4 to T6:                                                                            signal at 6.94 ppm                                                            (1H integ.)                                                                   doublet at 4.31 ppm                                                           (4H integ. - .sup.3 J = 6.5 Hz)                                               multiplet between 4.91 and                                                    5.35 ppm (4H)                                                                 multiplet between 5.62 and                                                    6.17 ppm (2H)                                                Thioureas T7 to T9:                                                                            quadruplet at 3.51 ppm                                                        (2H integ.)                                                                   signal at 7.79 ppm                                                            (integ. 1H)                                                                   signal at 6.98 ppm                                                            (integ. 1H)                                                                   singlet at 2.34 ppm                                                           (6H integ.)                                                                   multiplet between 2.31 and                                                    2.98 ppm (4H integ.)                                         Thioureas T10 to T12:                                                                          quadruplet at 3.48 ppm                                                        (2H integ.)                                                                   signal at 7.59 ppm                                                            (1H integ.)                                                                   signal at 7.96 ppm                                                            (1H integ.)                                                                   singlet at 2.19 ppm                                                           (6H integ.)                                                                   triplet at 2.34 ppm                                                           (2H integ.)                                                                   quintuplet at 1.71 ppm                                                        (2H integ.)                                                  Thioureas T13 and T14:                                                                         multiplet at 4.00 ppm                                                         12H integ.)                                                  Thioureas T15 and T16:                                                                         signal at 8.98 ppm                                                            (1H integ.)                                                                   multiplet at 7.25 ppm                                                         (6H integ.)                                                  Thioureas T17 to T20:                                                                          signal at 6.98 ppm                                                            (2H integ.)                                                                   quadruplet at 3.47 ppm                                                        (2H integ. - .sup.3 J = 6.5 Hz)                                               multiplet between 1.13 and                                                    1.9 ppm (4H or 12H int.)                                     Thioureas T21 to T24:                                                                          signal at 7.00 ppm                                                            (1H integ.)                                                  ______________________________________                                    

EXAMPLE 19

0.01 mole of thiourea T8 in solution in a minimum of chloroform and 0.05moles of methyl iodide are introduced into a reactor equipped with amagnetic stirrer and a condenser, and the mixture is then heated at 60°C. for one hour. A white precipitate is then seen. The chloroform isthen evaporated off and the residue is washed abundantly with ether andthen filtered off.

A white solid is thus obtained, which is the salt of formula ##STR17##which melts at 97° C. Yield: 97%.

The surface tension of an aqueous solution containing 0.1% of this saltis 19.2 mN m⁻¹ at 25° C. The interfacial tension of an aqueous solutioncontaining 0.1% of this salt, in equilibrium with cyclohexane, is 5.8 mNm⁻¹ at 25° C.

By proceeding in the same way with thiourea T9, the following salt##STR18## which melts at 93° C., is obtained in a 96% yield.

The surface tension of an aqueous solution containing 0.1% of this saltis 15.5 mN m⁻¹ at 25° C. The interfacial tension of an aqueous solutioncontaining 0.1% of this salt, in equilibrium with cyclohexane, is 6.4 mNm.-1 at 25° C.

EXAMPLE 20

0.01 mole of thiourea T8 in solution in a minimum of chloroform and 0.01mole of one of the quaternizing agents R-Br referred to in the firstcolumn of Table 5 below are introduced into a reactor equipped with amagnetic stirrer and a condenser. The mixture is then heated at 60° C.for 2 hours and the chloroform is then evaporated off and the residue iswashed abundantly with ethyl ether.

This yields the corresponding quaternary salts of formula: ##STR19##which are colorless or slightly orange-colored pastes. These salts arecompletely water-soluble. Their yield and the surface tension at 25° C.of an aqueous solution at a concentration of 0.1% are shown in thesecond and third columns of Table 5.

                  TABLE 5                                                         ______________________________________                                        Quaternizing agent                                                            R.sup.3Br       Yield (%) γs (mN m.sup.-1)                              ______________________________________                                        HOC.sub.2 H.sub.4Br                                                                           70        15.4                                                CH.sub.2CHCH.sub.2Br                                                                          95        16.4                                                 ##STR20##      95        17.4                                                ______________________________________                                    

EXAMPLE 21

By starting with the aliphatic bromides C_(n) H_(2n+1) Br referred to inthe second column of Table 6 below and with thioureas of formula:##STR21## whose perfluoroalkyl radical R_(F) is referred to in the firstcolumn of Table 6, the salts of formula: ##STR22## were prepared by thefollowing procedure:

0.01 mole of thiourea (V) in solution in a minimum of chloroform and 0.01mole of aliphatic bromide C_(n) H_(2n+1) Br are introduced into areactor equipped with a magnetic stirrer and a condenser and the mixtureis then heated in refluxing chloroform for 96 hours. The chloroform isthen evaporated off and the residue is washed abundantly with petroleumether to remove the impurities and to precipitate the ammonium salt offormula (VI) which, after removal of the petroleum ether, in most casestakes the form of a colorless paste.

However, if precipitation of the quaternary salt (VI) in petroleum etherpresents difficulties, the mixture must be cooled to 0° C. for a fewhours; a translucent oil then appears, which is separated from thesolvent by decanting, it being possible for the operation to be repeatedonce. The expected ammonium compound is then obtained in the form of atranslucent oil.

The surface tension Ys and interfacial tension Yi (relative tocyclohexane) of the ammonium salt in question, which are measured at 25°C. in aqueous solution at a concentration of 0.1%, are shown in thefourth and fifth columns of Table 6, the third column showing the yield.

                  TABLE 6                                                         ______________________________________                                        AMMONIUM SALTS OF FORMULA (VI)                                                                        γs                                                                           γi                                         RF        C.sub.n H.sub.2n+1                                                                     Yield (%)     (mN m.sup.-1)                                ______________________________________                                        C.sub.4 F.sub.9                                                                         C.sub.8 H.sub.17                                                                       60            19.7 0.7                                     C.sub.4 F.sub.9                                                                         C.sub.12 H.sub.25                                                                      78            23.1 1.9                                     C.sub.4 F.sub.9                                                                         C.sub.16 H.sub.33                                                                      65            26.8 2.1                                     C.sub.6 F.sub.13                                                                        C.sub.8 H.sub.17                                                                       74            15.9 1.4                                     C.sub.6 F.sub.13                                                                        C.sub.12 H.sub.25                                                                      67            17.5 0.8                                     C.sub.6 F.sub.13                                                                        C.sub.16 H.sub.33                                                                      70            20.3 0.7                                     C.sub.8 F.sub.17                                                                        C.sub.5 H.sub.11                                                                       62            16   2                                       C.sub.8 F.sub.17                                                                        C.sub.8 H.sub.17                                                                       75            15.9 3.2                                     C.sub.8 F.sub.17                                                                        C.sub.12 H.sub.25                                                                      72            15.2 2.2                                     ______________________________________                                    

EXAMPLE 22

0.02 moles of thiourea T8 in solution in a minimum of chloroform and0.01 mole of 1,2-dibromoethane are introduced into a reactor equippedwith a magnetic stirrer and a condenser. The mixture is heated underreflux for 24 hours and the chloroform is then evaporated off and theresidue is taken up with ethyl ether.

The double quaternary salt precipitates. After removal of the solventthe double quaternary salt of formula: ##STR23## is obtained in a 75%yield.

The surface tension of an aqueous solution containing 0.1% of this saltis 15.5 mN m⁻¹ at 25° C. The interfacial tension in relation tocyclohexane in the same conditions is 5.5 mN m⁻¹ .

By proceeding in the same manner starting with 1,3-dibromopropane, thedouble quaternary salt of formula: ##STR24## is obtained in a 98% yield.The surface tension of an aqueous solution containing 0.1% of this saltis 16.4 mN m⁻¹ at 25° C. The interfacial tension relative to cyclohexanein the same conditions is 7.7 mN m¹.

EXAMPLE 23

0.01 mole of thiourea T8 dissolved in a minimum of tetrahydrofuran isintroduced into a reactor equipped with a magnetic stirrer and acondenser and aqueous hydrogen peroxide is then added in excess (20%).The mixture is then heated at 40° C. with stirring for 3 hours and isthen left for twelve hours at room temperature. A small quantity ofwater (approximately 1 ml) is then added and the mixture is heated to40° C. for 15 minutes.

The tetrahydrofuran is then evaporated off and the residue is taken upwith methanol and then filtered. The filtrate is then evaporated off anda beige pasty solid which is the N-oxide of formula: ##STR25## isobtained in a 65% yield.

The surface tension of an aqueous solution containing 0.1% of thisN-oxide at 25° C. is 16.3 mN m⁻¹

EXAMPLE 24

0.01 mole of thiourea T8 and 25 ml of isopropanol are introduced into areactor equipped with a magnetic stirrer and a condenser and a solutionof 1.25 g of sodium chloroacetate in 25 ml isopropanol is then added.The mixture is then heated at 90° C. for 20 hours, the solvent isevaporated off and the residue is taken up with ethyl ether. Afterremoval of the liquid phase, the pasty solid obtained is washed withmethanol and the filtrate is evaporated to dryness. A pasty white solidwhich is the betaine of formula: ##STR26## is thus obtained in a 65%yield.

The surface tension of an aqueous solution containing 1 0.1% of thisbetaine is 16.2 mN m⁻¹.

The preceding references are hereby incorporated by reference.

Although the invention has been described in conjunction with specificembodiments, it is evident that many alternatives and variations will beapparent to those skilled in the art in light of the foregoingdescription. Accordingly, the invention is intended to embrace all ofthe alternatives and variations that fall within the spirit and scope ofthe appended claims.

We claim:
 1. Polyfluoroalkyl nitrogen compounds, comprising thosecorresponding to the formula:

    R.sub.F (CH.sub.2).sub.2 --X

wherein X is a thiourea group --NH--CS--A and A is chosen from thegroups (A1) to (A5) of formulae: ##STR27## each of Q and Q', which areidentical or different, denotes and alkylene bridge of 2 to 8 carbonatoms, R denotes an unsubstituted linear alkyl radical containing from 1to 4 carbon atoms, R¹ denotes a linear or branched alkyl radicalcontaining form 1 to 18 carbon atoms and optionally substituted, andoptionally substituted aryl or aralkyl radical, and allyl, methallyl orpropargyl radical, a --(CH₂)₂ R'_(F) group or a Q--NR₂ group, saidoptional substituents being selected from at least one halogen atom, ahydroxyl or mercapto group, or a sulphonate or sulfate functional group,R² denotes a hydrogen atom, an alkyl radical as defined for R¹ or,provided that R¹ is an alkyl or allyl radical, and allyl radical, R³denotes an alkyl or aralkyl radical as defined for R¹, an allyl,methallyl or propargyl radical, or a --CH₂ S--(CH₂)₂ --R'_(F) group,Z(-) denotes a monovalent anion or its equivalent, and each of R_(F) andR'_(F), which are identical or different, denotes a linear or branchedperfluoroalkyl radical containing from 2 to 16 carbon atoms. 2.Compounds according to claim 1, wherein R¹ is an alkyl, aryl or aralkylradical substituted by at least one halogen atom, a hydroxyl or mercaptogroup, or a sulphonate or sulphate functional group.
 3. Compoundsaccording to claim 1, wherein each of the radicals R_(F) and R'_(F)contains from 4 to 12 carbon atoms.